code.delx.au - gnu-emacs/blob - lisp/calculator.el

   1 ;;; calculator.el --- A [not so] simple calculator for Emacs.
   2
   3 ;; Copyright (C) 1998, 2000 by Free Software Foundation, Inc.
   4
   5 ;; Author: Eli Barzilay <eli@www.barzilay.org>
   6 ;; Keywords: tools, convenience
   7 ;; Time-stamp: <2000-11-07 15:04:06 eli>
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify it
  12 ;; under the terms of the GNU General Public License as published by the
  13 ;; Free Software Foundation; either version 2, or (at your option) any
  14 ;; later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful, but
  17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 ;; General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  24 ;; MA 02111-1307, USA.
  25
  26 ;;;============================================================================
  27 ;;; Commentary:
  28 ;;
  29 ;; A calculator for Emacs.
  30 ;; Why should you reach for your mouse to get xcalc (calc.exe, gcalc or
  31 ;; whatever), when you have Emacs running already?
  32 ;;
  33 ;; If this is not part of your Emacs distribution, then simply bind
  34 ;; `calculator' to a key and make it an autoloaded function, e.g.:
  35 ;;   (autoload 'calculator "calculator"
  36 ;;     "Run the Emacs calculator." t)
  37 ;;   (global-set-key [(control return)] 'calculator)
  38 ;;
  39 ;; Written by Eli Barzilay: Maze is Life!  eli@barzilay.org
  40 ;;                                         http://www.barzilay.org/
  41 ;;
  42 ;; For latest version, check
  43 ;;     http://www.barzilay.org/misc/calculator.el
  44
  45 (eval-and-compile
  46   (if (fboundp 'defgroup) nil
  47     (defmacro defgroup (&rest forms) nil)
  48     (defmacro defcustom (s v d &rest r) (list 'defvar s v d))))
  49
  50 ;;;============================================================================
  51 ;;; Customization:
  52
  53 (defgroup calculator nil
  54   "Simple Emacs calculator."
  55   :prefix "calculator"
  56   :version "21.1"
  57   :group 'tools
  58   :group 'convenience)
  59
  60 (defcustom calculator-electric-mode nil
  61   "*Run `calculator' electrically, in the echo area.
  62 Electric mode saves some place but changes the way you interact with the
  63 calculator."
  64   :type  'boolean
  65   :group 'calculator)
  66
  67 (defcustom calculator-use-menu t
  68   "*Make `calculator' create a menu.
  69 Note that this requires easymenu.  Must be set before loading."
  70   :type  'boolean
  71   :group 'calculator)
  72
  73 (defcustom calculator-bind-escape nil
  74   "*If non-nil, set escape to exit the calculator."
  75   :type  'boolean
  76   :group 'calculator)
  77
  78 (defcustom calculator-unary-style 'postfix
  79   "*Value is either 'prefix or 'postfix.
  80 This determines the default behavior of unary operators."
  81   :type    '(choice (const prefix) (const postfix))
  82   :group   'calculator)
  83
  84 (defcustom calculator-prompt "Calc=%s> "
  85   "*The prompt used by the Emacs calculator.
  86 It should contain a \"%s\" somewhere that will indicate the i/o radixes,
  87 this string will be a two-character string as described in the
  88 documentation for `calculator-mode'."
  89   :type  'string
  90   :group 'calculator)
  91
  92 (defcustom calculator-number-digits 3
  93   "*The calculator's number of digits used for standard display.
  94 Used by the `calculator-standard-display' function - it will use the
  95 format string \"%.NC\" where this number is N and C is a character given
  96 at runtime."
  97   :type  'string
  98   :group 'calculator)
  99
 100 (defcustom calculator-remove-zeros t
 101   "*Non-nil value means delete all redundant zero decimal digits.
 102 If this value is not t, and not nil, redundant zeros are removed except
 103 for one and if it is nil, nothing is removed.
 104 Used by the `calculator-remove-zeros' function."
 105   :type  '(choice (const t) (const leave-decimal) (const nil))
 106   :group 'calculator)
 107
 108 (defcustom calculator-displayer '(std ?n)
 109   "*A displayer specification for numerical values.
 110 This is the displayer used to show all numbers in an expression.  Result
 111 values will be displayed according to the first element of
 112 `calculator-displayers'.
 113
 114 The displayer is a symbol, a string or an expression.  A symbol should
 115 be the name of a one-argument function, a string is used with a single
 116 argument and an expression will be evaluated with the variable `num'
 117 bound to whatever should be displayed.  If it is a function symbol, it
 118 should be able to handle special symbol arguments, currently 'left and
 119 'right which will be sent by special keys to modify display parameters
 120 associated with the displayer function (for example to change the number
 121 of digits displayed).
 122
 123 An exception to the above is the case of the list (std C) where C is a
 124 character, in this case the `calculator-standard-displayer' function
 125 will be used with this character for a format string.")
 126
 127 (defcustom calculator-displayers
 128   '(((std ?n) "Standard dislpay, decimal point or scientific")
 129     (calculator-eng-display "Eng display")
 130     ((std ?f) "Standard display, decimal point")
 131     ((std ?e) "Standard dislpay, scientific")
 132     ("%S"     "Emacs printer"))
 133   "*A list of displayers.
 134 Each element is a list of a displayer and a description string.  The
 135 first element is the one which is curently used, this is for the display
 136 of result values not values in expressions.  A displayer specification
 137 is the same as the values that can be stored in `calculator-displayer'.
 138
 139 `calculator-rotate-displayer' rotates this list."
 140   :type  'sexp
 141   :group 'calculator)
 142
 143 (defcustom calculator-paste-decimals t
 144   "*If non-nil, convert pasted integers so they have a decimal point.
 145 This makes it possible to paste big integers since they will be read as
 146 floats, otherwise the Emacs reader will fail on them."
 147   :type  'boolean
 148   :group 'calculator)
 149
 150 (defcustom calculator-2s-complement nil
 151   "*If non-nil, show negative numbers in 2s complement in radix modes.
 152 Otherwise show as a negative number."
 153   :type  'boolean
 154   :group 'calculator)
 155
 156 (defcustom calculator-mode-hook nil
 157   "*List of hook functions for `calculator-mode' to run."
 158   :type  'hook
 159   :group 'calculator)
 160
 161 (defcustom calculator-user-registers nil
 162   "*An association list of user-defined register bindings.
 163 Each element in this list is a list of a character and a number that
 164 will be stored in that character's register.
 165
 166 For example, use this to define the golden ratio number:
 167   (setq calculator-user-registers '((?g .  1.61803398875)))
 168 before you load calculator."
 169   :type  '(repeat (cons character number))
 170   :set   '(lambda (_ val)
 171             (and (boundp 'calculator-registers)
 172                  (setq calculator-registers
 173                        (append val calculator-registers)))
 174             (setq calculator-user-registers val))
 175   :group 'calculator)
 176
 177 (defcustom calculator-user-operators nil
 178   "*A list of additional operators.
 179 This is a list in the same format as specified in the documentation for
 180 `calculator-operators', that you can use to bind additional calculator
 181 operators.  It is probably not a good idea to modify this value with
 182 `customize' since it is too complex...
 183
 184 Examples:
 185
 186 * A very simple one, adding a postfix \"x-to-y\" conversion keys, using
 187   t as a prefix key:
 188
 189   (setq calculator-user-operators
 190         '((\"tf\" cl-to-fr (+ 32 (/ (* X 9) 5)) 1)
 191           (\"tc\" fr-to-cl (/ (* (- X 32) 5) 9) 1)
 192           (\"tp\" kg-to-lb (/ X 0.453592)       1)
 193           (\"tk\" lb-to-kg (* X 0.453592)       1)
 194           (\"tF\" mt-to-ft (/ X 0.3048)         1)
 195           (\"tM\" ft-to-mt (* X 0.3048)         1)))
 196
 197 * Using a function-like form is very simple, X for an argument (Y the
 198   second in case of a binary operator), TX is a truncated version of X
 199   and F does a recursive call, Here is a [very inefficient] Fibonacci
 200   number calculation:
 201
 202   (add-to-list 'calculator-user-operators
 203                '(\"F\" fib (if (<= TX 1)
 204                          1
 205                          (+ (F (- TX 1)) (F (- TX 2)))) 0))
 206
 207   Note that this will be either postfix or prefix, according to
 208   `calculator-unary-style'."
 209   :type  '(repeat (list string symbol sexp integer integer))
 210   :group 'calculator)
 211
 212 ;;;============================================================================
 213 ;;; Code:
 214
 215 ;;;----------------------------------------------------------------------------
 216 ;;; Variables
 217
 218 (defvar calculator-initial-operators
 219   '(;; "+"/"-" have keybindings of themselves, not calculator-ops
 220     ("=" =     identity        1 -1)
 221     (nobind "+" +  +           2  4)
 222     (nobind "-" -  -           2  4)
 223     (nobind "+" +  +          -1  9)
 224     (nobind "-" -  -          -1  9)
 225     ("(" \(    identity       -1 -1)
 226     (")" \)    identity       +1 10)
 227     ;; normal keys
 228     ("|"  or   (logior TX TY)  2  2)
 229     ("#"  xor  (logxor TX TY)  2  2)
 230     ("&"  and  (logand TX TY)  2  3)
 231     ("*"  *    *               2  5)
 232     ("/"  /    /               2  5)
 233     ("\\" div  (/ TX TY)       2  5)
 234     ("%"  rem  (% TX TY)       2  5)
 235     ("L"  log  log             2  6)
 236     ("S"  sin  (sin DX)        x  6)
 237     ("C"  cos  (cos DX)        x  6)
 238     ("T"  tan  (tan DX)        x  6)
 239     ("IS" asin (D (asin X))    x  6)
 240     ("IC" acos (D (acos X))    x  6)
 241     ("IT" atan (D (atan X))    x  6)
 242     ("Q"  sqrt sqrt            x  7)
 243     ("^"  ^    expt            2  7)
 244     ("!"  !    calculator-fact x  7)
 245     (";"  1/   (/ 1 X)         1  7)
 246     ("_"  -    -               1  8)
 247     ("~"  ~    (lognot TX)     x  8)
 248     (">"  repR calculator-repR 1  8)
 249     ("<"  repL calculator-repL 1  8)
 250     ("v"  avg  (/ (apply '+ L) (length L)) 0 8)
 251     ("l"  tot  (apply '+ L)    0 8)
 252     )
 253   "A list of initial operators.
 254 This is a list in the same format as `calculator-operators'.  Whenever
 255 `calculator' starts, it looks at the value of this variable, and if it
 256 is not empty, its contents is prepended to `calculator-operators' and
 257 the appropriate key bindings are made.
 258
 259 This variable is then reset to nil.  Don't use this if you want to add
 260 user-defined operators, use `calculator-user-operators' instead.")
 261
 262 (defvar calculator-operators nil
 263   "The calculator operators, each a list with:
 264
 265 1. The key that is bound to for this operation (usually a string);
 266
 267 2. The displayed symbol for this function;
 268
 269 3. The function symbol, or a form that uses the variables `X' and `Y',
 270    (if it is a binary operator), `TX' and `TY' (truncated integer
 271    versions), `DX' (converted to radians if degrees mode is on), `D'
 272    (function for converting radians to degrees if deg mode is on), `L'
 273    (list of saved values), `F' (function for recursive iteration calls)
 274    and evaluates to the function value - these variables are capital;
 275
 276 4. The function's arity, optional, one of: 2 => binary, -1 => prefix
 277    unary, +1 => postfix unary, 0 => a 0-arg operator func, non-number =>
 278    postfix/prefix as determined by `calculator-unary-style' (the
 279    default);
 280
 281 5. The function's precedence - should be in the range of 1 (lowest) to
 282    9 (highest) (optional, defaults to 1);
 283
 284 It it possible have a unary prefix version of a binary operator if it
 285 comes later in this list.  If the list begins with the symbol 'nobind,
 286 then no key binding will take place - this is only useful for predefined
 287 keys.
 288
 289 Use `calculator-user-operators' to add operators to this list, see its
 290 documentation for an example.")
 291
 292 (defvar calculator-stack nil
 293   "Stack contents - operations and operands.")
 294
 295 (defvar calculator-curnum nil
 296   "Current number being entered (as a string).")
 297
 298 (defvar calculator-stack-display nil
 299   "Cons of the stack and its string representation.")
 300
 301 (defvar calculator-char-radix
 302   '((?D . nil) (?B . bin) (?O . oct) (?H . hex) (?X . hex))
 303   "A table to convert input characters to corresponding radix symbols.")
 304
 305 (defvar calculator-output-radix nil
 306   "The mode for display, one of: nil (decimal), 'bin, 'oct or 'hex.")
 307
 308 (defvar calculator-input-radix nil
 309   "The mode for input, one of: nil (decimal), 'bin, 'oct or 'hex.")
 310
 311 (defvar calculator-deg nil
 312   "Non-nil if trig functions operate on degrees instead of radians.")
 313
 314 (defvar calculator-saved-list nil
 315   "A list of saved values collected.")
 316
 317 (defvar calculator-saved-ptr 0
 318   "The pointer to the current saved number.")
 319
 320 (defvar calculator-add-saved nil
 321   "Bound to t when a value should be added to the saved-list.")
 322
 323 (defvar calculator-display-fragile nil
 324   "When non-nil, we see something that the next digit should replace.")
 325
 326 (defvar calculator-buffer nil
 327   "The current calculator buffer.")
 328
 329 (defvar calculator-eng-extra nil
 330   "Internal value used by `calculator-eng-display'.")
 331
 332 (defvar calculator-eng-tmp-show nil
 333   "Internal value used by `calculator-eng-display'.")
 334
 335 (defvar calculator-last-opXY nil
 336   "The last binary operation and its arguments.
 337 Used for repeating operations in calculator-repR/L.")
 338
 339 (defvar calculator-registers ; use user-bindings first
 340   (append calculator-user-registers (list (cons ?e e) (cons ?p pi)))
 341   "The association list of calculator register values.")
 342
 343 (defvar calculator-saved-global-map nil
 344   "Saved global key map.")
 345
 346 (defvar calculator-restart-other-mode nil
 347   "Used to hack restarting with the electric mode changed.")
 348
 349 ;;;----------------------------------------------------------------------------
 350 ;;; Key bindings
 351
 352 (defvar calculator-mode-map nil
 353   "The calculator key map.")
 354
 355 (or calculator-mode-map
 356   (let ((map (make-sparse-keymap)))
 357     (suppress-keymap map t)
 358     (define-key map "i" nil)
 359     (define-key map "o" nil)
 360     (let ((p
 361            '((calculator-open-paren  "[")
 362              (calculator-close-paren "]")
 363              (calculator-op-or-exp   "+" "-" [kp-add] [kp-subtract])
 364              (calculator-digit       "0" "1" "2" "3" "4" "5" "6" "7" "8"
 365                                      "9" "a" "b" "c" "d" "f"
 366                                      [kp-0] [kp-1] [kp-2] [kp-3] [kp-4]
 367                                      [kp-5] [kp-6] [kp-7] [kp-8] [kp-9])
 368              (calculator-op          [kp-divide] [kp-multiply])
 369              (calculator-decimal     "." [kp-decimal])
 370              (calculator-exp         "e")
 371              (calculator-dec/deg-mode "D")
 372              (calculator-set-register "s")
 373              (calculator-get-register "g")
 374              (calculator-radix-mode        "H" "X" "O" "B")
 375              (calculator-radix-input-mode  "id" "ih" "ix" "io" "ib"
 376                                            "iD" "iH" "iX" "iO" "iB")
 377              (calculator-radix-output-mode "od" "oh" "ox" "oo" "ob"
 378                                            "oD" "oH" "oX" "oO" "oB")
 379              (calculator-rotate-displayer      "'")
 380              (calculator-rotate-displayer-back "\"")
 381              (calculator-displayer-left        "{")
 382              (calculator-displayer-right       "}")
 383              (calculator-saved-up      [up] [?\C-p])
 384              (calculator-saved-down    [down] [?\C-n])
 385              (calculator-quit          "q" [?\C-g])
 386              (calculator-enter         [enter] [linefeed] [kp-enter]
 387                                        [return] [?\r] [?\n])
 388              (calculator-save-on-list  " " [space])
 389              (calculator-clear-saved   [?\C-c] [(control delete)])
 390              (calculator-save-and-quit [(control return)]
 391                                        [(control kp-enter)])
 392              (calculator-paste         [insert] [(shift insert)] [mouse-2])
 393              (calculator-clear         [delete] [?\C-?] [?\C-d])
 394              (calculator-help          [?h] [??] [f1] [help])
 395              (calculator-copy          [(control insert)])
 396              (calculator-backspace     [backspace])
 397              )))
 398       (while p
 399         ;; reverse the keys so first defs come last - makes the more
 400         ;; sensible bindings visible in the menu
 401         (let ((func (car (car p))) (keys (reverse (cdr (car p)))))
 402           (while keys
 403             (define-key map (car keys) func)
 404             (setq keys (cdr keys))))
 405         (setq p (cdr p))))
 406     (if calculator-bind-escape
 407       (progn (define-key map [?\e] 'calculator-quit)
 408              (define-key map [escape] 'calculator-quit))
 409       (define-key map [?\e ?\e ?\e] 'calculator-quit))
 410     ;; make C-h work in text-mode
 411     (or window-system (define-key map [?\C-h] 'calculator-backspace))
 412     ;; set up a menu
 413     (if (and calculator-use-menu (not (boundp 'calculator-menu)))
 414       (let ((radix-selectors
 415              (mapcar (lambda (x)
 416                        `([,(nth 0 x)
 417                           (calculator-radix-mode ,(nth 2 x))
 418                           :style radio
 419                           :keys ,(nth 2 x)
 420                           :selected
 421                           (and
 422                            (eq calculator-input-radix ',(nth 1 x))
 423                            (eq calculator-output-radix ',(nth 1 x)))]
 424                          [,(concat (nth 0 x) " Input")
 425                           (calculator-radix-input-mode ,(nth 2 x))
 426                           :keys ,(concat "i" (downcase (nth 2 x)))
 427                           :style radio
 428                           :selected
 429                           (eq calculator-input-radix ',(nth 1 x))]
 430                          [,(concat (nth 0 x) " Output")
 431                           (calculator-radix-output-mode ,(nth 2 x))
 432                           :keys ,(concat "o" (downcase (nth 2 x)))
 433                           :style radio
 434                           :selected
 435                           (eq calculator-output-radix ',(nth 1 x))]))
 436                      '(("Decimal"     nil "D")
 437                        ("Binary"      bin "B")
 438                        ("Octal"       oct "O")
 439                        ("Hexadecimal" hex "H"))))
 440             (op '(lambda (name key)
 441                         `[,name (calculator-op ,key) :keys ,key])))
 442         (easy-menu-define
 443          calculator-menu map "Calculator menu."
 444          `("Calculator"
 445            ["Help"
 446             (let ((last-command 'calculator-help)) (calculator-help))
 447             :keys "?"]
 448            "---"
 449            ["Copy"  calculator-copy]
 450            ["Paste" calculator-paste]
 451            "---"
 452            ["Electric mode"
 453             (progn (calculator-quit)
 454                    (setq calculator-restart-other-mode t)
 455                    (run-with-timer 0.1 nil '(lambda () (message nil)))
 456                    ;; the message from the menu will be visible,
 457                    ;; couldn't make it go away...
 458                    (calculator))
 459             :active (not calculator-electric-mode)]
 460            ["Normal mode"
 461             (progn (setq calculator-restart-other-mode t)
 462                    (calculator-quit))
 463             :active calculator-electric-mode]
 464            "---"
 465            ("Functions"
 466             ,(funcall op "Repeat-right" ">")
 467             ,(funcall op "Repeat-left"  "<")
 468             "------General------"
 469             ,(funcall op "Reciprocal"   ";")
 470             ,(funcall op "Log"          "L")
 471             ,(funcall op "Square-root"  "Q")
 472             ,(funcall op "Factorial"    "!")
 473             "------Trigonometric------"
 474             ,(funcall op "Sinus"        "S")
 475             ,(funcall op "Cosine"       "C")
 476             ,(funcall op "Tangent"      "T")
 477             ,(funcall op "Inv-Sinus"    "IS")
 478             ,(funcall op "Inv-Cosine"   "IC")
 479             ,(funcall op "Inv-Tangent"  "IT")
 480             "------Bitwise------"
 481             ,(funcall op "Or"           "|")
 482             ,(funcall op "Xor"          "#")
 483             ,(funcall op "And"          "&")
 484             ,(funcall op "Not"          "~"))
 485            ("Saved List"
 486             ["Eval+Save"      calculator-save-on-list]
 487             ["Prev number"    calculator-saved-up]
 488             ["Next number"    calculator-saved-down]
 489             ["Delete current" calculator-clear
 490              :active (and calculator-display-fragile
 491                           calculator-saved-list
 492                           (= (car calculator-stack)
 493                              (nth calculator-saved-ptr
 494                                   calculator-saved-list)))]
 495             ["Delete all" calculator-clear-saved]
 496             "---"
 497             ,(funcall op "List-total"   "l")
 498             ,(funcall op "List-average" "v"))
 499            ("Registers"
 500             ["Get register" calculator-get-register]
 501             ["Set register" calculator-set-register])
 502            ("Modes"
 503             ["Radians"
 504              (progn
 505                (and (or calculator-input-radix calculator-output-radix)
 506                     (calculator-radix-mode "D"))
 507                (and calculator-deg (calculator-dec/deg-mode)))
 508              :keys "D"
 509              :style radio
 510              :selected (not (or calculator-input-radix
 511                                 calculator-output-radix
 512                                 calculator-deg))]
 513             ["Degrees"
 514              (progn
 515                (and (or calculator-input-radix calculator-output-radix)
 516                     (calculator-radix-mode "D"))
 517                (or calculator-deg (calculator-dec/deg-mode)))
 518              :keys "D"
 519              :style radio
 520              :selected (and calculator-deg
 521                             (not (or calculator-input-radix
 522                                      calculator-output-radix)))]
 523             "---"
 524             ,@(mapcar 'car radix-selectors)
 525             ("Seperate I/O"
 526              ,@(mapcar (lambda (x) (nth 1 x)) radix-selectors)
 527              "---"
 528              ,@(mapcar (lambda (x) (nth 2 x)) radix-selectors)))
 529            ("Decimal Dislpay"
 530             ,@(mapcar (lambda (d)
 531                         (vector (cadr d)
 532                                 ;; Note: inserts actual object here
 533                                 `(calculator-rotate-displayer ',d)))
 534                       calculator-displayers)
 535             "---"
 536             ["Change Display Left"  calculator-displayer-left]
 537             ["Change Display Right" calculator-displayer-right])
 538            "---"
 539            ["Copy+Quit" calculator-save-and-quit]
 540            ["Quit"      calculator-quit]))))
 541     (setq calculator-mode-map map)))
 542
 543 ;;;----------------------------------------------------------------------------
 544 ;;; Startup and mode stuff
 545
 546 (defun calculator-mode ()
 547   ;; this help is also used as the major help screen
 548   "A [not so] simple calculator for Emacs.
 549
 550 This calculator is used in the same way as other popular calculators
 551 like xcalc or calc.exe - but using an Emacs interface.
 552
 553 Expressions are entered using normal infix notation, parens are used as
 554 normal.  Unary functions are usually postfix, but some depends on the
 555 value of `calculator-unary-style' (if the style for an operator below is
 556 specified, then it is fixed, otherwise it depends on this variable).
 557 `+' and `-' can be used as either binary operators or prefix unary
 558 operators.  Numbers can be entered with exponential notation using `e',
 559 except when using a non-decimal radix mode for input (in this case `e'
 560 will be the hexadecimal digit).
 561
 562 Here are the editing keys:
 563 * `RET' `='      evaluate the current expression
 564 * `C-insert'     copy the whole current expression to the `kill-ring'
 565 * `C-return'     evaluate, save result the `kill-ring' and exit
 566 * `insert'       paste a number if the one was copied (normally)
 567 * `delete' `C-d' clear last argument or whole expression (hit twice)
 568 * `backspace'    delete a digit or a previous expression element
 569 * `h' `?'        pop-up a quick reference help
 570 * `ESC' `q'      exit (`ESC' can be used if `calculator-bind-escape' is
 571                  non-nil, otherwise use three consecutive `ESC's)
 572
 573 These operators are pre-defined:
 574 * `+' `-' `*' `/' the common binary operators
 575 * `\\' `%'         integer division and reminder
 576 * `_' `;'         postfix unary negation and reciprocal
 577 * `^' `L'         binary operators for x^y and log(x) in base y
 578 * `Q' `!'         unary square root and factorial
 579 * `S' `C' `T'     unary trigonometric operators - sin, cos and tan
 580 * `|' `#' `&' `~' bitwise operators - or, xor, and, not
 581
 582 The trigonometric functions can be inverted if prefixed with an `I', see
 583 below for the way to use degrees instead of the default radians.
 584
 585 Two special postfix unary operators are `>' and `<': whenever a binary
 586 operator is performed, it is remembered along with its arguments; then
 587 `>' (`<') will apply the same operator with the same right (left)
 588 argument.
 589
 590 hex/oct/bin modes can be set for input and for display separately.
 591 Another toggle-able mode is for using degrees instead of radians for
 592 trigonometric functions.
 593 The keys to switch modes are (`X' is shortcut for `H'):
 594 * `D'             switch to all-decimal mode, or toggle degrees/radians
 595 * `B' `O' `H' `X' binary/octal/hexadecimal modes for input & display
 596 * `i' `o'         followed by one of `D' `B' `O' `H' `X' (case
 597                   insensitive) sets only the input or display radix mode
 598 The prompt indicates the current modes:
 599 * \"D=\": degrees mode;
 600 * \"?=\": (? is B/O/H) this is the radix for both input and output;
 601 * \"=?\": (? is B/O/H) the display radix (when input is decimal);
 602 * \"??\": (? is D/B/O/H) 1st char for input radix, 2nd for display.
 603
 604 Also, the quote character can be used to switch display modes for
 605 decimal numbers (double-quote rotates back), and the two brace
 606 characters (\"{\" and \"}\" change display parameters that these
 607 displayers use (if they handle such).
 608
 609 Values can be saved for future reference in either a list of saved
 610 values, or in registers.
 611
 612 The list of saved values is useful for statistics operations on some
 613 collected data.  It is possible to navigate in this list, and if the
 614 value shown is the current one on the list, an indication is displayed
 615 as \"[N]\" if this is the last number and there are N numbers, or
 616 \"[M/N]\" if the M-th value is shown.
 617 * `SPC'            evaluate the current value as usual, but also adds
 618                    the result to the list of saved values
 619 * `l' `v'          computes total / average of saved values
 620 * `up' `C-p'       browse to the previous value in the list
 621 * `down' `C-n'     browse to the next value in the list
 622 * `delete' `C-d'   remove current value from the list (if it is on it)
 623 * `C-delete' `C-c' delete the whole list
 624
 625 Registers are variable-like place-holders for values:
 626 * `s' followed by a character attach the current value to that character
 627 * `g' followed by a character fetches the attached value
 628
 629 There are many variables that can be used to customize the calculator.
 630 Some interesting customization variables are:
 631 * `calculator-electric-mode'  use only the echo-area electrically.
 632 * `calculator-unary-style'    set most unary ops to pre/postfix style.
 633 * `calculator-user-registers' to define user-preset registers.
 634 * `calculator-user-operators' to add user-defined operators.
 635 See the documentation for these variables, and \"calculator.el\" for
 636 more information.
 637
 638 \\{calculator-mode-map}"
 639   (interactive)
 640   (kill-all-local-variables)
 641   (setq major-mode 'calculator-mode)
 642   (setq mode-name "Calculator")
 643   (use-local-map calculator-mode-map)
 644   (run-hooks 'calculator-mode-hook))
 645
 646 (eval-when-compile (require 'electric) (require 'ehelp))
 647
 648 ;;;###autoload
 649 (defun calculator ()
 650   "Run the Emacs calculator.
 651 See the documentation for `calculator-mode' for more information."
 652   (interactive)
 653   (if calculator-restart-other-mode
 654     (setq calculator-electric-mode (not calculator-electric-mode)))
 655   (if calculator-initial-operators
 656     (progn (calculator-add-operators calculator-initial-operators)
 657            (setq calculator-initial-operators nil)
 658            ;; don't change this since it is a customization variable,
 659            ;; its set function will add any new operators
 660            (calculator-add-operators calculator-user-operators)))
 661   (if calculator-electric-mode
 662     (save-window-excursion
 663       (progn (require 'electric) (message nil)) ; hide load message
 664       (let (old-g-map old-l-map (echo-keystrokes 0)
 665             (garbage-collection-messages nil)) ; no gc msg when electric
 666         ;; strange behavior in FSF: doesn't always select correct
 667         ;; minibuffer.  I have no idea how to fix this
 668         (setq calculator-buffer (window-buffer (minibuffer-window)))
 669         (select-window (minibuffer-window))
 670         (calculator-reset)
 671         (calculator-update-display)
 672         (setq old-l-map (current-local-map))
 673         (setq old-g-map (current-global-map))
 674         (setq calculator-saved-global-map (current-global-map))
 675         (use-local-map nil)
 676         (use-global-map calculator-mode-map)
 677         (unwind-protect
 678             (catch 'calculator-done
 679               (Electric-command-loop
 680                'calculator-done
 681                ;; can't use 'noprompt, bug in electric.el
 682                '(lambda () 'noprompt)
 683                nil
 684                (lambda (x y) (calculator-update-display))))
 685           (and calculator-buffer
 686                (catch 'calculator-done (calculator-quit)))
 687           (use-local-map old-l-map)
 688           (use-global-map old-g-map))))
 689     (progn
 690       (setq calculator-buffer
 691             (or (and (bufferp calculator-buffer)
 692                      (buffer-live-p calculator-buffer)
 693                      calculator-buffer)
 694                 (if calculator-electric-mode
 695                   (get-buffer-create "*calculator*")
 696                   (let ((split-window-keep-point nil)
 697                         (window-min-height 2))
 698                     (select-window
 699                      ;; maybe leave two lines for our window because
 700                      ;; of the normal `raised' modeline in Emacs 21
 701                      (split-window-vertically
 702                       (- (window-height)
 703                          (if (and
 704                               (fboundp 'face-attr-construct)
 705                               (plist-get (face-attr-construct 'modeline)
 706                                          :box))
 707                            3
 708                            2))))
 709                     (switch-to-buffer
 710                      (get-buffer-create "*calculator*"))))))
 711       (set-buffer calculator-buffer)
 712       (calculator-mode)
 713       (setq buffer-read-only t)
 714       (calculator-reset)
 715       (message "Hit `?' For a quick help screen.")))
 716   (if (and calculator-restart-other-mode calculator-electric-mode)
 717     (calculator)))
 718
 719 ;;;----------------------------------------------------------------------------
 720 ;;; Operatos
 721
 722 (defun calculator-op-arity (op)
 723   "Return OP's arity, 2, +1 or -1."
 724   (let ((arity (or (nth 3 op) 'x)))
 725     (if (numberp arity)
 726       arity
 727       (if (eq calculator-unary-style 'postfix) +1 -1))))
 728
 729 (defun calculator-op-prec (op)
 730   "Return OP's precedence for reducing when inserting into the stack.
 731 Defaults to 1."
 732   (or (nth 4 op) 1))
 733
 734 (defun calculator-add-operators (more-ops)
 735   "This function handles operator addition.
 736 Adds MORE-OPS to `calculator-operator', called initially to handle
 737 `calculator-initial-operators' and `calculator-user-operators'."
 738   (let ((added-ops nil))
 739     (while more-ops
 740       (or (eq (car (car more-ops)) 'nobind)
 741           (let ((i -1) (key (car (car more-ops))))
 742             ;; make sure the key is undefined, so it's easy to define
 743             ;; prefix keys
 744             (while (< (setq i (1+ i)) (length key))
 745               (or (keymapp
 746                    (lookup-key calculator-mode-map
 747                                (substring key 0 (1+ i))))
 748                   (progn
 749                     (define-key
 750                       calculator-mode-map (substring key 0 (1+ i)) nil)
 751                     (setq i (length key)))))
 752             (define-key calculator-mode-map key 'calculator-op)))
 753       (setq added-ops (cons (if (eq (car (car more-ops)) 'nobind)
 754                               (cdr (car more-ops))
 755                               (car more-ops))
 756                             added-ops))
 757       (setq more-ops (cdr more-ops)))
 758     ;; added-ops come first, but in correct order
 759     (setq calculator-operators
 760           (append (nreverse added-ops) calculator-operators))))
 761
 762 ;;;----------------------------------------------------------------------------
 763 ;;; Display stuff
 764
 765 (defun calculator-reset ()
 766   "Reset calculator variables."
 767   (or calculator-restart-other-mode
 768       (setq calculator-stack           nil
 769             calculator-curnum          nil
 770             calculator-stack-display   nil
 771             calculator-display-fragile nil))
 772   (setq calculator-restart-other-mode nil)
 773   (calculator-update-display))
 774
 775 (defun calculator-get-prompt ()
 776   "Return a string to display.
 777 The string is set not to exceed the screen width."
 778   (let* ((calculator-prompt
 779           (format calculator-prompt
 780                   (cond
 781                     ((or calculator-output-radix calculator-input-radix)
 782                      (if (eq calculator-output-radix
 783                              calculator-input-radix)
 784                        (concat
 785                         (char-to-string
 786                          (car (rassq calculator-output-radix
 787                                      calculator-char-radix)))
 788                         "=")
 789                        (concat
 790                         (if calculator-input-radix
 791                           (char-to-string
 792                            (car (rassq calculator-input-radix
 793                                        calculator-char-radix)))
 794                           "=")
 795                         (char-to-string
 796                          (car (rassq calculator-output-radix
 797                                      calculator-char-radix))))))
 798                     (calculator-deg "D=")
 799                     (t "=="))))
 800          (prompt
 801           (concat calculator-prompt
 802                   (cdr calculator-stack-display)
 803                   (cond (calculator-curnum
 804                          ;; number being typed
 805                          (concat calculator-curnum "_"))
 806                         ((and (= 1 (length calculator-stack))
 807                               calculator-display-fragile)
 808                          ;; only the result is shown, next number will
 809                          ;; restart
 810                          nil)
 811                         (t
 812                          ;; waiting for a number or an operator
 813                          "?"))))
 814          (trim (- (length prompt) (1- (window-width)))))
 815     (if (<= trim 0)
 816       prompt
 817       (concat calculator-prompt
 818               (substring prompt (+ trim (length calculator-prompt)))))))
 819
 820 (defun calculator-curnum-value ()
 821   "Get the numeric value of the displayed number string as a float."
 822   (if calculator-input-radix
 823     (let ((radix
 824            (cdr (assq calculator-input-radix
 825                       '((bin . 2) (oct . 8) (hex . 16)))))
 826           (i -1) (value 0))
 827       ;; assume valid input (upcased & characters in range)
 828       (while (< (setq i (1+ i)) (length calculator-curnum))
 829         (setq value
 830               (+ (let ((ch (aref calculator-curnum i)))
 831                    (- ch (if (<= ch ?9) ?0 (- ?A 10))))
 832                  (* radix value))))
 833       value)
 834     (car
 835      (read-from-string
 836       (cond
 837         ((equal "." calculator-curnum)
 838          "0.0")
 839         ((string-match "[eE][+-]?$" calculator-curnum)
 840          (concat calculator-curnum "0"))
 841         ((string-match "\\.[0-9]\\|[eE]" calculator-curnum)
 842          calculator-curnum)
 843         ((string-match "\\." calculator-curnum)
 844          ;; do this because Emacs reads "23." as an integer
 845          (concat calculator-curnum "0"))
 846         ((stringp calculator-curnum)
 847          (concat calculator-curnum ".0"))
 848         (t "0.0"))))))
 849
 850 (defun calculator-rotate-displayer (&optional new-disp)
 851   "Switch to the next displayer on the `calculator-displayers' list.
 852 Can be called with an optional argument NEW-DISP to force rotation to
 853 that argument."
 854   (interactive)
 855   (setq calculator-displayers
 856         (if (and new-disp (memq new-disp calculator-displayers))
 857           (let ((tmp nil))
 858             (while (not (eq (car calculator-displayers) new-disp))
 859               (setq tmp (cons (car calculator-displayers) tmp))
 860               (setq calculator-displayers (cdr calculator-displayers)))
 861             (setq calculator-displayers
 862                   (nconc calculator-displayers (nreverse tmp))))
 863           (nconc (cdr calculator-displayers)
 864                  (list (car calculator-displayers)))))
 865   (message "Using %s." (cadr (car calculator-displayers)))
 866   (if calculator-electric-mode
 867     (progn (sit-for 1) (message nil)))
 868   (calculator-enter))
 869
 870 (defun calculator-rotate-displayer-back ()
 871   "Like `calculator-rotate-displayer', but rotates modes back."
 872   (interactive)
 873   (calculator-rotate-displayer (car (last calculator-displayers))))
 874
 875 (defun calculator-displayer-left ()
 876   "Send the current displayer function a 'left argument.
 877 This is used to modify display arguments (if the current displayer
 878 function supports this)."
 879   (interactive)
 880   (and (car calculator-displayers)
 881        (let ((disp (caar calculator-displayers)))
 882          (cond ((symbolp disp) (funcall disp 'left))
 883                ((and (consp disp) (eq 'std (car disp)))
 884                 (calculator-standard-displayer 'left (cadr disp)))))))
 885
 886 (defun calculator-displayer-right ()
 887   "Send the current displayer function a 'right argument.
 888 This is used to modify display arguments (if the current displayer
 889 function supports this)."
 890   (interactive)
 891   (and (car calculator-displayers)
 892        (let ((disp (caar calculator-displayers)))
 893          (cond ((symbolp disp) (funcall disp 'right))
 894                ((and (consp disp) (eq 'std (car disp)))
 895                 (calculator-standard-displayer 'right (cadr disp)))))))
 896
 897 (defun calculator-remove-zeros (numstr)
 898   "Get a number string NUMSTR and remove unnecessary zeroes.
 899 the behavior of this function is controlled by
 900 `calculator-remove-zeros'."
 901   (cond ((and (eq calculator-remove-zeros t)
 902               (string-match "\\.0+\\([eE][+-]?[0-9]*\\)?$" numstr))
 903          ;; remove all redundant zeros leaving an integer
 904          (if (match-beginning 1)
 905            (concat (substring numstr 0 (match-beginning 0))
 906                    (match-string 1 numstr))
 907            (substring numstr 0 (match-beginning 0))))
 908         ((and calculator-remove-zeros
 909               (string-match
 910                "\\..\\([0-9]*[1-9]\\)?\\(0+\\)\\([eE][+-]?[0-9]*\\)?$"
 911                numstr))
 912          ;; remove zeros, except for first after the "."
 913          (if (match-beginning 3)
 914            (concat (substring numstr 0 (match-beginning 2))
 915                    (match-string 3 numstr))
 916            (substring numstr 0 (match-beginning 2))))
 917         (t numstr)))
 918
 919 (defun calculator-standard-displayer (num char)
 920   "Standard display function, used to display NUM.
 921 Its behavior is determined by `calculator-number-digits' and the given
 922 CHAR argument (both will be used to compose a format string).  If the
 923 char is \"n\" then this function will choose one between %f or %e, this
 924 is a work around %g jumping to exponential notation too fast.
 925
 926 The special 'left and 'right symbols will make it change the current
 927 number of digits displayed (`calculator-number-digits').
 928
 929 It will also remove redundant zeros from the result."
 930   (if (symbolp num)
 931     (cond ((eq num 'left)
 932            (and (> calculator-number-digits 0)
 933                 (setq calculator-number-digits
 934                       (1- calculator-number-digits))
 935                 (calculator-enter)))
 936           ((eq num 'right)
 937            (setq calculator-number-digits
 938                  (1+ calculator-number-digits))
 939            (calculator-enter)))
 940     (let ((str (format
 941                 (concat "%."
 942                         (number-to-string calculator-number-digits)
 943                         (if (eq char ?n)
 944                           (let ((n (abs num)))
 945                             (if (or (< n 0.001) (> n 1e8)) "e" "f"))
 946                           (string char)))
 947                 num)))
 948       (calculator-remove-zeros str))))
 949
 950 (defun calculator-eng-display (num)
 951   "Display NUM in engineering notation.
 952 The number of decimal digits used is controlled by
 953 `calculator-number-digits', so to change it at runtime you have to use
 954 the 'left or 'right when one of the standard modes is used."
 955   (if (symbolp num)
 956     (cond ((eq num 'left)
 957            (setq calculator-eng-extra
 958                  (if calculator-eng-extra
 959                    (1+ calculator-eng-extra)
 960                    1))
 961            (let ((calculator-eng-tmp-show t)) (calculator-enter)))
 962           ((eq num 'right)
 963            (setq calculator-eng-extra
 964                  (if calculator-eng-extra
 965                    (1- calculator-eng-extra)
 966                    -1))
 967            (let ((calculator-eng-tmp-show t)) (calculator-enter))))
 968     (let ((exp 0))
 969       (and (not (= 0 num))
 970            (progn
 971              (while (< (abs num) 1.0)
 972                (setq num (* num 1000.0)) (setq exp (- exp 3)))
 973              (while (> (abs num) 999.0)
 974                (setq num (/ num 1000.0)) (setq exp (+ exp 3)))
 975              (and calculator-eng-tmp-show
 976                   (not (= 0 calculator-eng-extra))
 977                   (let ((i calculator-eng-extra))
 978                     (while (> i 0)
 979                       (setq num (* num 1000.0)) (setq exp (- exp 3))
 980                       (setq i (1- i)))
 981                     (while (< i 0)
 982                       (setq num (/ num 1000.0)) (setq exp (+ exp 3))
 983                       (setq i (1+ i)))))))
 984       (or calculator-eng-tmp-show (setq calculator-eng-extra nil))
 985       (let ((str (format (concat "%." calculator-number-digits "f")
 986                          num)))
 987         (concat (let ((calculator-remove-zeros
 988                        ;; make sure we don't leave integers
 989                        (and calculator-remove-zeros 'x)))
 990                   (calculator-remove-zeros str))
 991                 "e" (number-to-string exp))))))
 992
 993 (defun calculator-num-to-string (num)
 994   "Convert NUM to a displayable string."
 995   (cond
 996     ((and (numberp num) calculator-output-radix)
 997      ;; print with radix - for binary I convert the octal number
 998      (let ((str (format (if (eq calculator-output-radix 'hex) "%x" "%o")
 999                         (calculator-truncate
1000                          (if calculator-2s-complement num (abs num))))))
1001        (if (eq calculator-output-radix 'bin)
1002          (let ((i -1) (s ""))
1003            (while (< (setq i (1+ i)) (length str))
1004              (setq s
1005                    (concat s
1006                            (cdr (assq (aref str i)
1007                                       '((?0 . "000") (?1 . "001")
1008                                         (?2 . "010") (?3 . "011")
1009                                         (?4 . "100") (?5 . "101")
1010                                         (?6 . "110") (?7 . "111")))))))
1011            (string-match "^0*\\(.+\\)" s)
1012            (setq str (match-string 1 s))))
1013        (upcase
1014         (if (and (not calculator-2s-complement) (< num 0))
1015           (concat "-" str)
1016           str))))
1017     ((and (numberp num) (car calculator-displayers))
1018      (let ((disp (if (= 1 (length calculator-stack))
1019                    ;; customizable display for a single value
1020                    (caar calculator-displayers)
1021                    calculator-displayer)))
1022        (cond ((stringp disp) (format disp num))
1023              ((symbolp disp) (funcall disp num))
1024              ((and (consp disp)
1025                    (eq 'std (car disp)))
1026                              (calculator-standard-displayer
1027                               num (cadr disp)))
1028              ((listp disp)   (eval disp))
1029              (t              (prin1-to-string num t)))))
1030     ;; operators are printed here
1031     (t (prin1-to-string (nth 1 num) t))))
1032
1033 (defun calculator-update-display (&optional force)
1034   "Update the display.
1035 If optional argument FORCE is non-nil, don't use the cached string."
1036   (set-buffer calculator-buffer)
1037   ;; update calculator-stack-display
1038   (if (or force
1039           (not (eq (car calculator-stack-display) calculator-stack)))
1040     (setq calculator-stack-display
1041           (cons calculator-stack
1042                 (if calculator-stack
1043                   (concat
1044                    (mapconcat 'calculator-num-to-string
1045                               (reverse calculator-stack)
1046                               " ")
1047                    " "
1048                    (and calculator-display-fragile
1049                         calculator-saved-list
1050                         (= (car calculator-stack)
1051                            (nth calculator-saved-ptr
1052                                 calculator-saved-list))
1053                         (if (= 0 calculator-saved-ptr)
1054                           (format "[%s]" (length calculator-saved-list))
1055                           (format "[%s/%s]"
1056                                   (- (length calculator-saved-list)
1057                                      calculator-saved-ptr)
1058                                   (length calculator-saved-list)))))
1059                   ""))))
1060   (let ((inhibit-read-only t))
1061     (erase-buffer)
1062     (insert (calculator-get-prompt)))
1063   (set-buffer-modified-p nil)
1064   (if calculator-display-fragile
1065     (goto-char (1+ (length calculator-prompt)))
1066     (goto-char (1- (point)))))
1067
1068 ;;;----------------------------------------------------------------------------
1069 ;;; Stack computations
1070
1071 (defun calculator-reduce-stack (prec)
1072   "Reduce the stack using top operator.
1073 PREC is a precedence - reduce everything with higher precedence."
1074   (while
1075       (cond
1076         ((and (cdr (cdr calculator-stack))         ; have three values
1077               (consp   (nth 0 calculator-stack))   ; two operators & num
1078               (numberp (nth 1 calculator-stack))
1079               (consp   (nth 2 calculator-stack))
1080               (eq '\) (nth 1 (nth 0 calculator-stack)))
1081               (eq '\( (nth 1 (nth 2 calculator-stack))))
1082          ;; reduce "... ( x )" --> "... x"
1083          (setq calculator-stack
1084                (cons (nth 1 calculator-stack)
1085                      (nthcdr 3 calculator-stack)))
1086          ;; another iteration
1087          t)
1088         ((and (cdr (cdr calculator-stack))         ; have three values
1089               (numberp (nth 0 calculator-stack))   ; two nums & operator
1090               (consp   (nth 1 calculator-stack))
1091               (numberp (nth 2 calculator-stack))
1092               (= 2 (calculator-op-arity            ; binary operator
1093                     (nth 1 calculator-stack)))
1094               (<= prec                             ; with higher prec.
1095                   (calculator-op-prec (nth 1 calculator-stack))))
1096          ;; reduce "... x op y" --> "... r", r is the result
1097          (setq calculator-stack
1098                (cons (calculator-funcall
1099                       (nth 2 (nth 1 calculator-stack))
1100                       (nth 2 calculator-stack)
1101                       (nth 0 calculator-stack))
1102                      (nthcdr 3 calculator-stack)))
1103          ;; another iteration
1104          t)
1105         ((and (>= (length calculator-stack) 2)     ; have two values
1106               (numberp (nth 0 calculator-stack))   ; number & operator
1107               (consp   (nth 1 calculator-stack))
1108               (= -1 (calculator-op-arity           ; prefix-unary op
1109                      (nth 1 calculator-stack)))
1110               (<= prec                             ; with higher prec.
1111                   (calculator-op-prec (nth 1 calculator-stack))))
1112          ;; reduce "... op x" --> "... r" for prefix op
1113          (setq calculator-stack
1114                (cons (calculator-funcall
1115                       (nth 2 (nth 1 calculator-stack))
1116                       (nth 0 calculator-stack))
1117                      (nthcdr 2 calculator-stack)))
1118          ;; another iteration
1119          t)
1120         ((and (cdr calculator-stack)               ; have two values
1121               (consp   (nth 0 calculator-stack))   ; operator & number
1122               (numberp (nth 1 calculator-stack))
1123               (= +1 (calculator-op-arity           ; postfix-unary op
1124                      (nth 0 calculator-stack)))
1125               (<= prec                             ; with higher prec.
1126                   (calculator-op-prec (nth 0 calculator-stack))))
1127          ;; reduce "... x op" --> "... r" for postfix op
1128          (setq calculator-stack
1129                (cons (calculator-funcall
1130                       (nth 2 (nth 0 calculator-stack))
1131                       (nth 1 calculator-stack))
1132                      (nthcdr 2 calculator-stack)))
1133          ;; another iteration
1134          t)
1135         ((and calculator-stack                     ; have one value
1136               (consp (nth 0 calculator-stack))     ; an operator
1137               (= 0 (calculator-op-arity            ; 0-ary op
1138                     (nth 0 calculator-stack))))
1139          ;; reduce "... op" --> "... r" for 0-ary op
1140          (setq calculator-stack
1141                (cons (calculator-funcall
1142                       (nth 2 (nth 0 calculator-stack)))
1143                      (nthcdr 1 calculator-stack)))
1144          ;; another iteration
1145          t)
1146         ((and (cdr calculator-stack)               ; have two values
1147               (numberp (nth 0 calculator-stack))   ; both numbers
1148               (numberp (nth 1 calculator-stack)))
1149          ;; get rid of redundant numbers:
1150          ;;   reduce "... y x" --> "... x"
1151          ;; needed for 0-ary ops that puts more values
1152          (setcdr calculator-stack (cdr (cdr calculator-stack))))
1153         (t ;; no more iterations
1154            nil))))
1155
1156 (defun calculator-funcall (f &optional X Y)
1157   "If F is a symbol, evaluate (F X Y).
1158 Otherwise, it should be a list, evaluate it with X, Y bound to the
1159 arguments."
1160   ;; remember binary ops for calculator-repR/L
1161   (if Y (setq calculator-last-opXY (list f X Y)))
1162   (condition-case nil
1163       ;; there used to be code here that returns 0 if the result was
1164       ;; smaller than calculator-epsilon (1e-15).  I don't think this is
1165       ;; necessary now.
1166       (if (symbolp f)
1167         (cond ((and X Y) (funcall f X Y))
1168               (X         (funcall f X))
1169               (t         (funcall f)))
1170         ;; f is an expression
1171         (let* ((__f__ f) ; so we can get this value below...
1172                (TX (calculator-truncate X))
1173                (TY (and Y (calculator-truncate Y)))
1174                (DX (if calculator-deg (/ (* X pi) 180) X))
1175                (L  calculator-saved-list)
1176                (Fbound (fboundp 'F))
1177                (Fsave  (and Fbound (symbol-function 'F)))
1178                (Dbound (fboundp 'D))
1179                (Dsave  (and Dbound (symbol-function 'D))))
1180           ;; a shortened version of flet
1181           (fset 'F (function
1182                     (lambda (&optional x y)
1183                       (calculator-funcall __f__ x y))))
1184           (fset 'D (function
1185                     (lambda (x)
1186                       (if calculator-deg (/ (* x 180) pi) x))))
1187           (unwind-protect (eval f)
1188             (if Fbound (fset 'F Fsave) (fmakunbound 'F))
1189             (if Dbound (fset 'D Dsave) (fmakunbound 'D)))))
1190     (error 0)))
1191
1192 (eval-when-compile ; silence the compiler
1193   (or (fboundp 'event-key)
1194       (defun event-key (&rest _) nil))
1195   (or (fboundp 'key-press-event-p)
1196       (defun key-press-event-p (&rest _) nil)))
1197
1198 ;;;----------------------------------------------------------------------------
1199 ;;; Input interaction
1200
1201 (defun calculator-last-input (&optional keys)
1202   "Last char (or event or event sequence) that was read.
1203 Optional string argument KEYS will force using it as the keys entered."
1204   (let ((inp (or keys (this-command-keys))))
1205     (if (or (stringp inp) (not (arrayp inp)))
1206       inp
1207       ;; this translates kp-x to x and [tries to] create a string to
1208       ;; lookup operators
1209       (let* ((i -1) (converted-str (make-string (length inp) ? )) k)
1210         ;; converts an array to a string the ops lookup with keypad
1211         ;; input
1212         (while (< (setq i (1+ i)) (length inp))
1213           (setq k (aref inp i))
1214           ;; if Emacs will someday have a event-key, then this would
1215           ;; probably be modified anyway
1216           (and (fboundp 'event-key) (key-press-event-p k)
1217                (event-key k) (setq k (event-key k)))
1218           ;; assume all symbols are translatable with an ascii-character
1219           (and (symbolp k)
1220                (setq k (or (get k 'ascii-character) ? )))
1221           (aset converted-str i k))
1222         converted-str))))
1223
1224 (defun calculator-clear-fragile (&optional op)
1225   "Clear the fragile flag if it was set, then maybe reset all.
1226 OP is the operator (if any) that caused this call."
1227   (if (and calculator-display-fragile
1228            (or (not op)
1229                (= -1 (calculator-op-arity op))
1230                (= 0 (calculator-op-arity op))))
1231     ;; reset if last calc finished, and now get a num or prefix or 0-ary
1232     ;; op
1233     (calculator-reset))
1234   (setq calculator-display-fragile nil))
1235
1236 (defun calculator-digit ()
1237   "Enter a single digit."
1238   (interactive)
1239   (let ((inp (aref (calculator-last-input) 0)))
1240     (if (and (or calculator-display-fragile
1241                  (not (numberp (car calculator-stack))))
1242              (cond
1243                ((not calculator-input-radix)     (<= inp ?9))
1244                ((eq calculator-input-radix 'bin) (<= inp ?1))
1245                ((eq calculator-input-radix 'oct) (<= inp ?7))
1246                (t t)))
1247       ;; enter digit if starting a new computation or have an op on the
1248       ;; stack
1249       (progn
1250         (calculator-clear-fragile)
1251         (let ((digit (upcase (char-to-string inp))))
1252           (if (equal calculator-curnum "0")
1253             (setq calculator-curnum nil))
1254           (setq calculator-curnum
1255                 (concat (or calculator-curnum "") digit)))
1256         (calculator-update-display)))))
1257
1258 (defun calculator-decimal ()
1259   "Enter a decimal period."
1260   (interactive)
1261   (if (and (not calculator-input-radix)
1262            (or calculator-display-fragile
1263                (not (numberp (car calculator-stack))))
1264            (not (and calculator-curnum
1265                      (string-match "[.eE]" calculator-curnum))))
1266     ;; enter the period on the same condition as a digit, only if no
1267     ;; period or exponent entered yet
1268     (progn
1269       (calculator-clear-fragile)
1270       (setq calculator-curnum (concat (or calculator-curnum "0") "."))
1271       (calculator-update-display))))
1272
1273 (defun calculator-exp ()
1274   "Enter an `E' exponent character, or a digit in hex input mode."
1275   (interactive)
1276   (if calculator-input-radix
1277     (calculator-digit)
1278     (if (and (or calculator-display-fragile
1279                  (not (numberp (car calculator-stack))))
1280              (not (and calculator-curnum
1281                        (string-match "[eE]" calculator-curnum))))
1282       ;; same condition as above, also no E so far
1283       (progn
1284         (calculator-clear-fragile)
1285         (setq calculator-curnum (concat (or calculator-curnum "1") "e"))
1286         (calculator-update-display)))))
1287
1288 (defun calculator-op (&optional keys)
1289   "Enter an operator on the stack, doing all necessary reductions.
1290 Optional string argument KEYS will force using it as the keys entered."
1291   (interactive)
1292   (catch 'op-error
1293     (let* ((last-inp (calculator-last-input keys))
1294            (op (assoc last-inp calculator-operators)))
1295       (calculator-clear-fragile op)
1296       (if (and calculator-curnum (/= (calculator-op-arity op) 0))
1297         (setq calculator-stack
1298               (cons (calculator-curnum-value) calculator-stack)))
1299       (setq calculator-curnum nil)
1300       (if (and (= 2 (calculator-op-arity op))
1301                (not (and calculator-stack
1302                          (numberp (nth 0 calculator-stack)))))
1303         ;; we have a binary operator but no number - search for a prefix
1304         ;; version
1305         (let ((rest-ops calculator-operators))
1306           (while (not (equal last-inp (car (car rest-ops))))
1307             (setq rest-ops (cdr rest-ops)))
1308           (setq op (assoc last-inp (cdr rest-ops)))
1309           (if (not (and op (= -1 (calculator-op-arity op))))
1310             ;;(error "Binary operator without a first operand")
1311             (progn
1312               (message "Binary operator without a first operand")
1313               (if calculator-electric-mode
1314                 (progn (sit-for 1) (message nil)))
1315               (throw 'op-error nil)))))
1316       (calculator-reduce-stack
1317        (cond ((eq (nth 1 op) '\() 10)
1318              ((eq (nth 1 op) '\)) 0)
1319              (t (calculator-op-prec op))))
1320       (if (or (and (= -1 (calculator-op-arity op))
1321                    (numberp (car calculator-stack)))
1322               (and (/= (calculator-op-arity op) -1)
1323                    (/= (calculator-op-arity op) 0)
1324                    (not (numberp (car calculator-stack)))))
1325         ;;(error "Unterminated expression")
1326         (progn
1327           (message "Unterminated expression")
1328           (if calculator-electric-mode
1329             (progn (sit-for 1) (message nil)))
1330           (throw 'op-error nil)))
1331       (setq calculator-stack (cons op calculator-stack))
1332       (calculator-reduce-stack (calculator-op-prec op))
1333       (and (= (length calculator-stack) 1)
1334            (numberp (nth 0 calculator-stack))
1335            ;; the display is fragile if it contains only one number
1336            (setq calculator-display-fragile t)
1337            ;; add number to the saved-list
1338            calculator-add-saved
1339            (if (= 0 calculator-saved-ptr)
1340              (setq calculator-saved-list
1341                    (cons (car calculator-stack) calculator-saved-list))
1342              (let ((p (nthcdr (1- calculator-saved-ptr)
1343                               calculator-saved-list)))
1344                (setcdr p (cons (car calculator-stack) (cdr p))))))
1345       (calculator-update-display))))
1346
1347 (defun calculator-op-or-exp ()
1348   "Either enter an operator or a digit.
1349 Used with +/- for entering them as digits in numbers like 1e-3 (there is
1350 no need for negative numbers since these are handled by unary
1351 operators)."
1352   (interactive)
1353   (if (and (not calculator-display-fragile)
1354            calculator-curnum
1355            (string-match "[eE]$" calculator-curnum))
1356     (calculator-digit)
1357     (calculator-op)))
1358
1359 ;;;----------------------------------------------------------------------------
1360 ;;; Input/output modes (not display)
1361
1362 (defun calculator-dec/deg-mode ()
1363   "Set decimal mode for display & input, if decimal, toggle deg mode."
1364   (interactive)
1365   (if calculator-curnum
1366     (setq calculator-stack
1367           (cons (calculator-curnum-value) calculator-stack)))
1368   (setq calculator-curnum nil)
1369   (if (or calculator-input-radix calculator-output-radix)
1370     (progn (setq calculator-input-radix nil)
1371            (setq calculator-output-radix nil))
1372     ;; already decimal - toggle degrees mode
1373     (setq calculator-deg (not calculator-deg)))
1374   (calculator-update-display t))
1375
1376 (defun calculator-radix-mode (&optional keys)
1377   "Set input and display radix modes.
1378 Optional string argument KEYS will force using it as the keys entered."
1379   (interactive)
1380   (calculator-radix-input-mode keys)
1381   (calculator-radix-output-mode keys))
1382
1383 (defun calculator-radix-input-mode (&optional keys)
1384   "Set input radix modes.
1385 Optional string argument KEYS will force using it as the keys entered."
1386   (interactive)
1387   (if calculator-curnum
1388     (setq calculator-stack
1389           (cons (calculator-curnum-value) calculator-stack)))
1390   (setq calculator-curnum nil)
1391   (setq calculator-input-radix
1392         (let ((inp (calculator-last-input keys)))
1393           (cdr (assq (upcase (aref inp (1- (length inp))))
1394                      calculator-char-radix))))
1395   (calculator-update-display))
1396
1397 (defun calculator-radix-output-mode (&optional keys)
1398   "Set display radix modes.
1399 Optional string argument KEYS will force using it as the keys entered."
1400   (interactive)
1401   (if calculator-curnum
1402     (setq calculator-stack
1403           (cons (calculator-curnum-value) calculator-stack)))
1404   (setq calculator-curnum nil)
1405   (setq calculator-output-radix
1406         (let ((inp (calculator-last-input keys)))
1407           (cdr (assq (upcase (aref inp (1- (length inp))))
1408                      calculator-char-radix))))
1409   (calculator-update-display t))
1410
1411 ;;;----------------------------------------------------------------------------
1412 ;;; Saved values list
1413
1414 (defun calculator-save-on-list ()
1415   "Evaluate current expression, put result on the saved values list."
1416   (interactive)
1417   (let ((calculator-add-saved t)) ; marks the result to be added
1418     (calculator-enter)))
1419
1420 (defun calculator-clear-saved ()
1421   "Clear the list of saved values in `calculator-saved-list'."
1422   (interactive)
1423   (setq calculator-saved-list nil)
1424   (setq calculator-saved-ptr 0)
1425   (calculator-update-display t))
1426
1427 (defun calculator-saved-move (n)
1428   "Go N elements up the list of saved values."
1429   (interactive)
1430   (and calculator-saved-list
1431        (or (null calculator-stack) calculator-display-fragile)
1432        (progn
1433          (setq calculator-saved-ptr
1434                (max (min (+ n calculator-saved-ptr)
1435                          (length calculator-saved-list))
1436                     0))
1437          (if (nth calculator-saved-ptr calculator-saved-list)
1438            (setq calculator-stack
1439                  (list (nth calculator-saved-ptr calculator-saved-list))
1440                  calculator-display-fragile t)
1441            (calculator-reset))
1442          (calculator-update-display))))
1443
1444 (defun calculator-saved-up ()
1445   "Go up the list of saved values."
1446   (interactive)
1447   (calculator-saved-move +1))
1448
1449 (defun calculator-saved-down ()
1450   "Go down the list of saved values."
1451   (interactive)
1452   (calculator-saved-move -1))
1453
1454 ;;;----------------------------------------------------------------------------
1455 ;;; Misc functions
1456
1457 (defun calculator-open-paren ()
1458   "Equivalents of `(' use this."
1459   (interactive)
1460   (calculator-op "("))
1461
1462 (defun calculator-close-paren ()
1463   "Equivalents of `)' use this."
1464   (interactive)
1465   (calculator-op ")"))
1466
1467 (defun calculator-enter ()
1468   "Evaluate current expression."
1469   (interactive)
1470   (calculator-op "="))
1471
1472 (defun calculator-backspace ()
1473   "Backward delete a single digit or a stack element."
1474   (interactive)
1475   (if calculator-curnum
1476     (setq calculator-curnum
1477           (if (> (length calculator-curnum) 1)
1478             (substring calculator-curnum
1479                        0 (1- (length calculator-curnum)))
1480             nil))
1481     (setq calculator-stack (cdr calculator-stack)))
1482   (calculator-update-display))
1483
1484 (defun calculator-clear ()
1485   "Clear current number."
1486   (interactive)
1487   (setq calculator-curnum nil)
1488   (cond
1489     ;; if the current number is from the saved-list - remove it
1490     ((and calculator-display-fragile
1491           calculator-saved-list
1492           (= (car calculator-stack)
1493              (nth calculator-saved-ptr calculator-saved-list)))
1494      (if (= 0 calculator-saved-ptr)
1495        (setq calculator-saved-list (cdr calculator-saved-list))
1496        (let ((p (nthcdr (1- calculator-saved-ptr)
1497                         calculator-saved-list)))
1498          (setcdr p (cdr (cdr p)))
1499          (setq calculator-saved-ptr (1- calculator-saved-ptr))))
1500      (if calculator-saved-list
1501        (setq calculator-stack
1502              (list (nth calculator-saved-ptr calculator-saved-list)))
1503        (calculator-reset)))
1504     ;; reset if fragile or double clear
1505     ((or calculator-display-fragile (eq last-command this-command))
1506      (calculator-reset)))
1507   (calculator-update-display))
1508
1509 (defun calculator-copy ()
1510   "Copy current number to the `kill-ring'."
1511   (interactive)
1512   (calculator-enter)
1513   ;; remove trailing spaces and and an index
1514   (let ((s (cdr calculator-stack-display)))
1515     (if (string-match "^\\([^ ]+\\) *\\(\\[[0-9/]+\\]\\)? *$" s)
1516       (setq s (match-string 1 s)))
1517     (kill-new s)))
1518
1519 (defun calculator-set-register (reg)
1520   "Set a register value for REG."
1521   (interactive "cRegister to store into: ")
1522   (let* ((as  (assq reg calculator-registers))
1523          (val (progn (calculator-enter) (car calculator-stack))))
1524     (if as
1525       (setcdr as val)
1526       (setq calculator-registers
1527             (cons (cons reg val) calculator-registers)))
1528     (message (format "[%c] := %S" reg val))))
1529
1530 (defun calculator-put-value (val)
1531   "Paste VAL as if entered.
1532 Used by `calculator-paste' and `get-register'."
1533   (if (and (numberp val)
1534            ;; (not calculator-curnum)
1535            (or calculator-display-fragile
1536                (not (numberp (car calculator-stack)))))
1537     (progn
1538       (calculator-clear-fragile)
1539       (setq calculator-curnum (calculator-num-to-string val))
1540       (calculator-update-display))))
1541
1542 (defun calculator-paste ()
1543   "Paste a value from the `kill-ring'."
1544   (interactive)
1545   (calculator-put-value
1546    (let ((str (current-kill 0)))
1547      (if calculator-paste-decimals
1548        (progn
1549          (string-match "\\([0-9]+\\)\\(\\.[0-9]+\\)?\\(e[0-9]+\\)?" str)
1550          (if (or (match-string 1 str)
1551                  (match-string 2 str)
1552                  (match-string 3 str))
1553            (setq str (concat (match-string 1 str)
1554                              (or (match-string 2 str) ".0")
1555                              (match-string 3 str))))))
1556      (condition-case nil (car (read-from-string str))
1557        (error nil)))))
1558
1559 (defun calculator-get-register (reg)
1560   "Get a value from a register REG."
1561   (interactive "cRegister to get value from: ")
1562   (calculator-put-value (cdr (assq reg calculator-registers))))
1563
1564 (defun calculator-help ()
1565   ;; this is used as the quick reference screen you get with `h'
1566   "Quick reference:
1567 * numbers/operators/parens/./e - enter expressions
1568   + - * / \\(div) %(rem) _(-X,postfix) ;(1/X,postfix) ^(exp) L(og)
1569   Q(sqrt) !(fact) S(in) C(os) T(an) |(or) #(xor) &(and) ~(not)
1570 * >/< repeats last binary operation with its 2nd (1st) arg as postfix op
1571 * I inverses next trig function        * '/\"/{} - display/display args
1572 * D         - switch to all-decimal, or toggle deg/rad mode
1573 * B/O/H/X   - binary/octal/hex mode for i/o (X is a shortcut for H)
1574 * i/o       - prefix for d/b/o/x - set only input/output modes
1575 * enter/=   - evaluate current expr.   * s/g      - set/get a register
1576 * space     - evaluate & save on list  * l/v      - list total/average
1577 * up/down/C-p/C-n - browse saved       * C-delete - clear all saved
1578 * C-insert  - copy whole expr.         * C-return - evaluate, copy, exit
1579 * insert    - paste a number           * backspace- delete backwards
1580 * delete    - clear argument or list value or whole expression (twice)
1581 * escape/q  - exit."
1582   (interactive)
1583   (if (eq last-command 'calculator-help)
1584     (let ((mode-name "Calculator")
1585           (major-mode 'calculator-mode)
1586           (g-map (current-global-map))
1587           (win (selected-window)))
1588       (require 'ehelp)
1589       (if calculator-electric-mode
1590         (use-global-map calculator-saved-global-map))
1591       (electric-describe-mode)
1592       (if calculator-electric-mode
1593         (use-global-map g-map))
1594       (select-window win) ; these are for XEmacs (also below)
1595       (message nil))
1596     (let ((one (one-window-p t))
1597           (win (selected-window))
1598           (help-buf (get-buffer-create "*Help*")))
1599       (save-window-excursion
1600         (with-output-to-temp-buffer "*Help*"
1601           (princ (documentation 'calculator-help)))
1602         (if one
1603           (shrink-window-if-larger-than-buffer
1604            (get-buffer-window help-buf)))
1605         (message
1606          "`%s' again for more help, any other key continues normally."
1607          (calculator-last-input))
1608         (select-window win)
1609         (sit-for 360))
1610       (select-window win))))
1611
1612 (defun calculator-quit ()
1613   "Quit calculator."
1614   (interactive)
1615   (set-buffer calculator-buffer)
1616   (let ((inhibit-read-only t)) (erase-buffer))
1617   (if (not calculator-electric-mode)
1618     (progn
1619       (condition-case nil
1620           (while (get-buffer-window calculator-buffer)
1621             (delete-window (get-buffer-window calculator-buffer)))
1622         (error nil))
1623       (kill-buffer calculator-buffer)))
1624   (setq calculator-buffer nil)
1625   (message "Calculator done.")
1626   (if calculator-electric-mode (throw 'calculator-done nil)))
1627
1628 (defun calculator-save-and-quit ()
1629   "Quit the calculator, saving the result on the `kill-ring'."
1630   (interactive)
1631   (calculator-enter)
1632   (calculator-copy)
1633   (calculator-quit))
1634
1635 (defun calculator-repR (x)
1636   "Repeats the last binary operation with its second argument and X.
1637 To use this, apply a binary operator (evaluate it), then call this."
1638   (if calculator-last-opXY
1639     ;; avoid rebinding calculator-last-opXY
1640     (let ((calculator-last-opXY calculator-last-opXY))
1641       (calculator-funcall
1642        (car calculator-last-opXY) x (nth 2 calculator-last-opXY)))
1643     x))
1644
1645 (defun calculator-repL (x)
1646   "Repeats the last binary operation with its first argument and X.
1647 To use this, apply a binary operator (evaluate it), then call this."
1648   (if calculator-last-opXY
1649     ;; avoid rebinding calculator-last-opXY
1650     (let ((calculator-last-opXY calculator-last-opXY))
1651       (calculator-funcall
1652        (car calculator-last-opXY) (nth 1 calculator-last-opXY) x))
1653     x))
1654
1655 (defun calculator-fact (x)
1656   "Simple factorial of X."
1657   (let ((r (if (<= x 10) 1 1.0)))
1658     (while (> x 0)
1659       (setq r (* r (truncate x)))
1660       (setq x (1- x)))
1661     r))
1662
1663 (defun calculator-truncate (n)
1664   "Truncate N, return 0 in case of overflow."
1665   (condition-case nil (truncate n) (error 0)))
1666
1667
1668 (provide 'calculator)
1669
1670 ;;; calculator.el ends here